This stone has been known by many names, but the word turquoise, which dates to the 16th century, is derived from an Old French word for “Turkish”, because the mineral was first brought to Europe from Turkey. Most American turquoise is of a low grade (called “chalk turquoise”); high iron levels mean greens and yellows predominate. Also not all “turquoise” on the market is actually turquoise but dyed howlite or magnesite.